/*
 * $Header:
 * /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons
 * //httpclient
 * /src/java/org/apache/commons/httpclient/methods/multipart/StringPart.java,v
 * 1.11 2004/04/18 23:51:37 jsdever Exp $ $Revision: 480424 $ $Date: 2006-11-29
 * 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many individuals on
 * behalf of the Apache Software Foundation. For more information on the Apache
 * Software Foundation, please see <http://www.apache.org/>.
 */

package com.microsoft.tfs.core.httpclient.methods.multipart;

import java.io.IOException;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.microsoft.tfs.core.httpclient.util.EncodingUtil;

/**
 * Simple string parameter for a multipart post
 *
 * @author <a href="mailto:mattalbright@yahoo.com">Matthew Albright</a>
 * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
 *
 * @since 2.0
 */
public class StringPart extends PartBase {

    /** Log object for this class. */
    private static final Log LOG = LogFactory.getLog(StringPart.class);

    /** Default content encoding of string parameters. */
    public static final String DEFAULT_CONTENT_TYPE = "text/plain";

    /** Default charset of string parameters */
    public static final String DEFAULT_CHARSET = "US-ASCII";

    /** Default transfer encoding of string parameters */
    public static final String DEFAULT_TRANSFER_ENCODING = "8bit";

    /** Contents of this StringPart. */
    private byte[] content;

    /** The String value of this part. */
    private final String value;

    /**
     * Constructor.
     *
     * @param name
     *        The name of the part
     * @param value
     *        the string to post
     * @param charset
     *        the charset to be used to encode the string, if <code>null</code>
     *        the {@link #DEFAULT_CHARSET default} is used
     */
    public StringPart(final String name, final String value, final String charset) {

        super(name, DEFAULT_CONTENT_TYPE, charset == null ? DEFAULT_CHARSET : charset, DEFAULT_TRANSFER_ENCODING);
        if (value == null) {
            throw new IllegalArgumentException("Value may not be null");
        }
        if (value.indexOf(0) != -1) {
            // See RFC 2048, 2.8. "8bit Data"
            throw new IllegalArgumentException("NULs may not be present in string parts");
        }
        this.value = value;
    }

    /**
     * Constructor.
     *
     * @param name
     *        The name of the part
     * @param value
     *        the string to post
     */
    public StringPart(final String name, final String value) {
        this(name, value, null);
    }

    /**
     * Gets the content in bytes. Bytes are lazily created to allow the charset
     * to be changed after the part is created.
     *
     * @return the content in bytes
     */
    private byte[] getContent() {
        if (content == null) {
            content = EncodingUtil.getBytes(value, getCharSet());
        }
        return content;
    }

    /**
     * Writes the data to the given OutputStream.
     *
     * @param out
     *        the OutputStream to write to
     * @throws IOException
     *         if there is a write error
     */
    @Override
    protected void sendData(final OutputStream out) throws IOException {
        LOG.trace("enter sendData(OutputStream)");
        out.write(getContent());
    }

    /**
     * Return the length of the data.
     *
     * @return The length of the data.
     * @throws IOException
     *         If an IO problem occurs
     * @see com.microsoft.tfs.core.httpclient.methods.multipart.Part#lengthOfData()
     */
    @Override
    protected long lengthOfData() throws IOException {
        LOG.trace("enter lengthOfData()");
        return getContent().length;
    }

    /*
     * (non-Javadoc)
     *
     * @see
     * org.apache.commons.httpclient.methods.multipart.BasePart#setCharSet(java
     * .lang.String)
     */
    @Override
    public void setCharSet(final String charSet) {
        super.setCharSet(charSet);
        content = null;
    }

}
